1. Field of the Invention
The present invention relates generally to medical devices, systems, apparatus, and methods for modifying nerve function and treating disease. More particularly, the present invention relates to methods and apparatus for exchanging energy or delivering active agents through the renal pelvis to modify sympathetic nerve activity in the adventitia of arteries and/or veins that surround the external surface of the renal pelvis in the kidney and in the afferent and efferent nerves within the muscles layers, urothelium and submucosa of the renal pelvis.
Hypertension, or high blood pressure, is a significant and growing health risk throughout the world. Hypertension can be caused by hyperactive renal sympathetic nerves which extend adjacent to the outside of the arteries and veins leading to a patient's kidney as well as within the wall of the renal pelvis. Renal nerve activity can be a significant cause of systemic hypertension, and it has long been known that disrupting renal nerve function can reduce blood pressure. More recently, hypertension therapies based on disrupting the renal nerves surrounding the renal arteries leading to the kidney (renal denervation) have been proposed and are described in the medical and patent literature.
Heretofore, most of the proposed renal denervation therapies have utilized an intravascular approach where a catheter is introduced into the arterial system and advanced to the main renal artery leading to the left or right kidney. Once located at a desired target site within the main renal artery, the catheter is used to deliver radiofrequency energy, heat, drugs, or the like to disrupt the function of the renal nerves which surround the artery. While effective, these techniques present a risk of injury to the renal artery and suffer from all the known disadvantages associated with intravascular access and therapies.
For these reasons, it would be desirable to provide alternative protocols and apparatus for accessing the renal nerves for the purpose of performing denervation or other renal nerve function disruptions which do not rely on intravascular access and which are not performed in the main renal artery leading to the kidney. It would be further desirable if such protocols and apparatus could be performed minimally invasively, would present a reduced risk of injury and trauma to the patient, were economical, and could be performed using simplified and scalable methods. In particular, it would be desirable to provide methods and apparatus for renal nerve denervation and modulation that could be performed using a natural orifice surgery. At least some of these objectives will be met by the inventions described herein below.
2. Description of the Background Art
U.S. Patent Publication No. 2011/0060324 describes apparatus, systems, and methods for performing thermally-induced renal neuromodulation by intravascular access. U.S. Patent Publication No. 2011/0104061 describes apparatus, systems, and methods for active agents to the renal arteries for achieving renal denervation. Published PCT Application WO2010/067360 describes methods and apparatus for modifying blood pressure and kidney function via stimulation of the urinary tract by stimulating the renal nerves.